Eyeball locating method and system

ABSTRACT

An eyeball locating system includes a display panel, an application program and a matrix optical sensor. The matrix optical sensor is disposed in the display panel. The application program controls the matrix optical sensor, executing an eyeball locating method to measure the movement of an eyeball including an eye white and a pupil. The method includes: providing a default graph showing the change of light energy; defining a default characteristic value of the pupil according to the default graph; shining light on the eye white and the pupil, a part of the light reflected by the eye white and the pupil to form a reflecting light; detecting the reflecting light energy to form a measured graph showing the change of reflected light energy; calculating a measured characteristic value according to the measured graph; and comparing the default with the measured characteristic values to determine the change of the pupil.

BACKGROUND OF THE INVENTION

(1) Field of the Invention

The present invention relates to an eyeball locating method and system,particularly to an eyeball locating method and system using an opticalsensor for determining the light reflected by the surface of theeyeball.

(2) Description of the Prior Art

Computer makes people's daily life more and more convenient, but formost disabled men, it is rather inconvenient to handle computer.

To help the disabled men to handle computer, several control methods ofthe man-machine interface system have been developed in the world, suchas hand joint control, voice control, electromyogram (EMG) behavior,shoulder control, gassing and so on. The common disadvantage among thesecontrol methods is that they are not capable of executing complexcontrol behaviors, and they are also unable to control the computerconveniently and real-timely because the control signal needs complexidentification and longer processing period.

To conquer these limits, the technology of using the movement of eyeballto control the computer emerges as the times require. The eyeballtracking system is most common, which is capable of controlling thecursor or keyboard of the computer by detecting the movement of theeyeball in real time. At present, the eyeball tracking system haspiezoelectric type, optical type and magnetic type according to thedetection principles.

The piezoelectric type is detecting the movement direction of theeyeball by the change of eye pressure, which is pasting thepiezoelectric sensor around the eyes, converting the eye pressure intoelectrical signal by the piezoelectric sensor and measuring theelectrical signal. However this system influences the measurement of theelectrical signal easily due to sweat.

The magnetic type is measuring the movement of the eyes by formingmagnetic field around the eyeball.

The optical type is capturing an eyeball image, coordinating the presenttarget position through algorithm of image analysis, sending the resultsto the personal computer and driving mouse to execute controlinstruction.

Refer to FIG. 1 for the head-mounted optical eyeball tracking system100. The eyeball tracking system 100 has a charge-coupled device (CCD)image detector 120, a screen 140 and a frame 160. The CCD image detector120 is electrically connected to the screen 140 and disposed on theframe 160 together with the screen 140. When an user 200 wears the frame160, the CCD image detector 120 and the screen 140 are fixed near theeyes of the user 200 by the frame 160. The screen 140 displays aplurality of the location points (not shown) for the user 200. When theuser 200 watches one of the location points on the screen 140, the CCDimage detector 120 captures his pupil image and performs binaryprocessing to get the position of the pupil.

Furthermore, the CCD image detector 120 is connected to a computer 180.The CCD image detector 120 collects and analyzes the pupil imagereal-timely, and converts it into a control order to command the cursorto handle the computer 180.

However, the user 200 of the eyeball tracking system 100 needs to wearthe frame 160 to increase success rate. The difficulty of the opticaldetection is when capturing the pupil image, the contrast ratio betweenthe pupil and the eye white is too low to measure, especially under thecondition of glasses obstruct, outer light disturb or eyeballpathological changes. In conclusion, the conventional eyeball trackingsystem 100 is limited in use and has low resolution, which makes it hardto apply in the view or browsing equipments or general medical occasion.

SUMMARY OF THE INVENTION

The present invention is to provide an eyeball locating method andsystem capable of rising the successful rate of eyeball locating, andbeing used more conveniently.

For achieving one, some or all of the above mentioned object, an eyeballlocating method is provided as an embodiment of the present invention.The eyeball locating method is used to measure the movement of aneyeball including an eye white and a pupil, the method includes thesteps of: providing a default graph showing the change of light energy;defining a default characteristic value of the pupil according to thedefault graph showing the change of light energy; shining light on theeye white and the pupil wherein at least a part of the light isreflected by the eye white and the pupil, so as to form a reflectinglight; detecting the energy of the reflecting light, so as to form ameasured graph showing the change of reflected light energy; calculatinga measured characteristic value according to the measured graph showingthe change of reflected light energy; and comparing the defaultcharacteristic value with the measured characteristic value to determinethe change of the pupil.

In one embodiment, the default characteristic value is the defaultcontrast ratio between the eye white and the pupil, and the measuredcharacteristic value is the measured contrast ratio between the eyewhite and the pupil.

In one embodiment, the default characteristic value is the default widthof the pupil, and the measured characteristic value is the measuredwidth of the pupil.

In above, the step of comparing the default characteristic value withthe measured characteristic value to determine the change of the pupilincludes determining the width, displacement or area change of thepupil. The step of determining the displacement change of the pupilincludes determining a vertical displacement, a horizontal displacementor a near-far displacement of the pupil.

In one embodiment, the eyeball locating method further includes thesteps of: providing a matrix optical sensor for shining the light anddetecting the energy of the reflected light; measuring the timedifference between the light emitted from the matrix optical sensor andthe reflecting light coming back to the matrix optical sensor; andcalculating the distance between the matrix optical sensor and theeyeball according to the light speed and the time difference.

An eyeball locating system is provided as an embodiment of the presentinvention. The eyeball locating system includes a display panel, amatrix optical sensor, an application program. The matrix optical sensoris disposed in the display panel, for shining light on the eyeball.Wherein, at least a part of the light is reflected by the eye white andthe pupil to form a reflecting light, and the matrix optical sensordetects the energy of the reflecting light. The application programprovides a default graph showing the change of light energy to define adefault characteristic value of the pupil, and controls the matrixoptical sensor, so as to form a measured graph showing the change ofreflected light energy according to the energy of the reflecting light.The application program calculates a measured characteristic valueaccording to the measured graph showing the change of reflected lightenergy and compares the default characteristic value with the measuredcharacteristic value to determine the change of the pupil.

In one embodiment, the matrix optical sensor is selected from the groupconsisting of a CCD sensor, a CMOS (complementary metal-oxidesemiconductor) sensor and an infrared sensor.

In one embodiment, the default or measured characteristic value is thecontrast ratio between the eye white and the pupil, or a width, adisplacement, an area of the pupil.

In above, both the default graph showing the change of light energy andthe measured graph showing the change of reflected light energy show therelationship between the light reflectivity and time.

Accordingly, the embodiments of the present invention compares thedefault characteristic value with the measure characteristic value basedon the default graph showing the change of light energy for determiningthe change of the pupil more accurately.

Other objectives, features and advantages of the present invention willbe further understood from the further technological features disclosedby the embodiments of the present invention wherein there are shown anddescribed preferred embodiments of this invention, simply by way ofillustration of modes best suited to carry out the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will now be specified with reference to itspreferred embodiment illustrated in the drawings, in which

FIG. 1 is a schematic view of the conventional optical eyeball trackingsystem;

FIG. 2 is a schematic view showing an embodiment of the eyeball locatingsystem according to the present invention;

FIG. 3 is a schematic view showing the eyeball structure and the defaultlight energy change graph according to an embodiment of the presentinvention;

FIG. 4 to FIG. 7 are schematic views showing the eyeball movement andthe measured reflected light energy change graph according to anembodiment of the present invention;

FIG. 8 is a schematic view showing another embodiment of the eyeballlocating system according to the present invention; and

FIG. 9 is a schematic flow chart showing an embodiment of the eyeballlocating method according to the present invention;

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which are shown by way of illustration specific embodiments inwhich the invention may be practiced. In this regard, directionalterminology, such as “top,” “bottom,” “front,” “back,” etc., is usedwith reference to the orientation of the Figure(s) being described. Thecomponents of the present invention can be positioned in a number ofdifferent orientations. As such, the directional terminology is used forpurposes of illustration and is in no way limiting. On the other hand,the drawings are only schematic and the sizes of components may beexaggerated for clarity. It is to be understood that other embodimentsmay be utilized and structural changes may be made without departingfrom the scope of the present invention. Also, it is to be understoodthat the phraseology and terminology used herein are for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having” and variations thereof herein ismeant to encompass the items listed thereafter and equivalents thereofas well as additional items. Unless limited otherwise, the terms“connected,” “coupled,” and “mounted” and variations thereof herein areused broadly and encompass direct and indirect connections, couplings,and mountings. Similarly, the terms “facing,” “faces” and variationsthereof herein are used broadly and encompass direct and indirectfacing, and “adjacent to” and variations thereof herein are used broadlyand encompass directly and indirectly “adjacent to”. Therefore, thedescription of “A” component facing “B” component herein may contain thesituations that “A” component directly faces “B” component directly orone or more additional components are between “A” component and “B”component. Also, the description of “A” component “adjacent to” “B”component herein may contain the situations that “A” component isdirectly “adjacent to” “B” component or one or more additionalcomponents are between “A” component and “B” component. Accordingly, thedrawings and descriptions will be regarded as illustrative in nature andnot as restrictive.

Refer to FIG. 2 for an eyeball locating system 300 to measure themovement of an eyeball 400. The eyeball locating system 300 includes adisplay panel 320, a first matrix optical sensor 340, a second matrixoptical sensor 360 and an application program 380. Referring to FIG. 3,the eyeball 400 has an eye white 420 and a pupil area 440 which has apupil 442 and an iris 444.

Referring to FIG. 2, the first matrix optical sensor 340 and the secondmatrix optical sensor 360 are disposed separately at two sides 322 and324 of the display panel 320. In this embodiment, both the first matrixoptical sensor 340 and the second matrix optical sensor 360 are thecomponents providing optical signal emission and induction, shininglight on the surface of the eyeball 400 respectively. At least a part ofthe light is reflected by the eye white 420 and the pupil 442, so as toform a reflecting light. Additionally, the first matrix optical sensor340 and the second matrix optical sensor 360 each detect the energy ofthe reflecting light from itself. It should be noted that the firstmatrix optical sensor 340 and the second matrix optical sensor 360 inthis embodiment are used to determine the energy of the reflecting lightaccurately, but the form or number of the matrix optical sensor is notlimited. In other words, applying single matrix optical sensor, or anindependent optical emitter with an optical sensor may also achieve theoptical signal emission and induction.

The application program 380 provides a default graph showing the changeof light energy, which may be used to define a default characteristicvalue of the pupil 442, such as the default contrast ratio of the eyewhite 420 and the pupil 442, the width, the area and the displacement ofthe pupil 442.

In addition, the application program 380 converts the energy of thereflecting light detected by the first matrix optical sensor 340 and thesecond matrix optical sensor 360 into numerical value by amicroprocessor (not shown), so as to form the first and the secondgraphs showing the change of reflected light energy, and calculates ameasured characteristic value of the pupil 442, such as the measuredcontrast ratio of the eye white 420 and the pupil 442, the width, thearea and the displacement of the pupil 442. By comparing the defaultcharacteristic value with the measured characteristic value, theapplication program 380 is able to determine the change of the pupil442.

Refer to FIG. 3 for the relationship between the default graph C showingthe change of light energy and the eye white 420, the iris 444 and thepupil 442. In a preferable embodiment, the longitudinal axis of thegraph C is optical reflectivity and the lateral axis is time. As shownin FIG. 3, the curves from the time t1 to t2 and the time t5 to t6 arethe default curves showing the optical reflectivity change of the eyewhite 420. The curve from the time t2 to t5 is the default curve showingthe optical reflectivity change of the pupil area 440. The curves fromthe time t2 to t3 and the time t4 to t5 are the default curves showingthe optical reflectivity change of the iris 444. The curve from the timet3 to t4 is the default curve showing the optical reflectivity change ofthe pupil 442.

As for the definition of the default and measured characteristic values,the example is taken below.

After the contrast ratio of the eye white 420 and the pupil 442 isdefined, the areas below the optical reflectivity change curves from thetime t1 to t2 and the time t3 to t4 may be calculated separately, andthen the ratio of the two areas is obtained. Another method to definethe contrast ratio of the eye white 420 and the pupil 442 is comparingthe height difference of the peaks of the optical reflectivity changecurves from the time t1 to t2 and the time t3 to t4, for example, theheight difference b in FIG. 3 represents the contrast ratio of the eyewhite 420 and the pupil 442.

Each time interval of the graph C showing the change of light energy hasa conversion relationship with the width, area or displacement of thepupil 442. For instance, assuming the scanning speed of the first matrixoptical sensor 340 or the second matrix optical sensor 360 is constantand the part scanned from t3 to t4 is the pupil 442, the width of thepupil 442 may be calculated by the scanning speed and the time intervalt3-t4. Thus, these default characteristic values may be definedaccording to the graph C showing the change of light energy.

Refer to FIG. 4 to FIG. 7 for the embodiment of the first or secondgraph showing the change of reflected light energy. The first matrixoptical sensor 340 and the second matrix optical sensor 360 are used inpractice to measure the eye white 420 and the pupil 442. Thereflectivity of the eye white 420 is high, so the signal of thereflecting light from the eye white 420 is strong, while thereflectivity of the pupil 442 is low, so the signal of the reflectinglight from the pupil 442 is weak. Accordingly, the first or second graphshowing the change of reflected light energy is obtained. By comparingthe waves of the graphs C1, C2, C3, C4 showing the change of reflectedlight energy with the default graph C showing the change of lightenergy, the eyeball 400 may be located. For convenient comparison withthe graph C, all the longitudinal axes of the graphs C1, C2, C3, C4 areoptical reflectivity and all the lateral axes are time.

Referring to FIG. 4, comparing the default graph C showing the change oflight energy (broken line) and the graph C1 showing the change ofreflected light energy, it appears that the current time intervals t1-t2and t5-t6 do not change, but the time intervals t2-t3′ and t4′-t5 areshorter than the default time intervals t2-t3 and t4-t5, while the timeinterval t3′-t4′ is longer than the default time interval t3-t4. Itrepresents that at this time the eyeball 400 is not running, but theiris 444 is shrunk and the pupil 442 is enlarged. In FIG. 4, the mark444′ stands for the shrunk iris and mark 442′ for the enlarged pupil. Incontrary, if the time intervals t2-t3′ and t4′-t5 are longer than thedefault time intervals t2-t3 and t4-t5, and the time interval t3′-t4′ isshorter than the default time interval t3-t4, it represents that theiris 444 is released and the pupil 442 is shrunk.

Referring to FIG. 5, comparing the default graph C showing the change oflight energy with the graph C2 showing the change of reflected lightenergy, it appears that when the time interval t1-t2′ is shorter thanthe default t1-t2′, but the t5′-t6 is longer than the default t5-t6, itrepresents that the eyeball 400 is running and the pupil 442 is movingto the left side of the image. In contrary, if the time interval t1-t2′is longer than the default t1-t2′, but t5′-t6 is shorter than thedefault t5-t6, it represents that the pupil 442 is moving to the rightside of the image. In addition, if the time intervals t2′-t3″, t3″-t4″,t4″-t5′ are different from the time intervals t2-t3, t3-t4, t4-t5 in thedefault graph C showing the change of light energy, it represents thatthe pupil 442 is enlarged or shrunk.

Referring to FIG. 6, the graph C3 showing the change of reflected lightenergy is the result of the default graph C showing the change of lightenergy shifting left. Under this circumstance, the time points T1, T2,T3, T4, T5, T6 depart from the default time points t1, t2, t3, t4, t5,t6, which means the eyeball 400 moves left, such as the head turning ormoving; the same principle is suitable for judging the eyeball 400moving right. As shown in FIG. 4 or FIG. 5, each time interval withint1-t6 changes along with the iris 442 changing or the eyeball 400turning.

Referring to FIG. 7, the graph C4 showing the change of reflected lightenergy shows when the default graph C showing the change of light energyis enlarged, the time points T1′, T2′, T3′ shift to the left of thedefault time points t1, t2, t3, and the time points T4′, T5′, T6′ shiftto the right of the default time points t4, t5, t6. It represents theeyeball 400 moves back and forth, such as the face moving back andforth. As shown in FIG. 4 or FIG. 5, each time interval within t1-t6changes along with the iris 442 changing or the eyeball 400 turning.

It may be speculated according to the above description that theembodiment of the present invention is also suitable for the eyeball 400running up and down.

According to FIG. 7, the movement of the eyeball 400 running back andforth may be detected, thus the distance change between the eyeball 400and the first matrix optical sensor 340 or the second matrix opticalsensor 360 may be defined and the backlight of the display panel 320 andthe font size on the image may be adjusted.

FIG. 8 provides another method to measure the distance between theeyeball 400 and the first matrix optical sensor 340 or the second matrixoptical sensor 360. Referring to FIG. 8, the first matrix optical sensor340 or the second matrix optical sensor 360 each shines a measuringlight on the surface of a left eyeball 400L and a right eyeball 400R,and the light is reflected by the left eyeball 400L and the righteyeball 400R to the first matrix optical sensor 340 or the second matrixoptical sensor 360 to form a time difference. According to light speedand the time difference, the distance D_(BL) between the first matrixoptical sensor 340 and the left eyeball 400L, the distance D_(BR)between the first matrix optical sensor 340 and the right eyeball 400R,the distance D_(AL) between the second matrix optical sensor 360 and theleft eyeball 400L, and the distance D_(AR) between the second matrixoptical sensor 360 and the right eyeball 400R are calculated.

In FIG. 8, the distance W between the first matrix optical sensor 340and the second matrix optical sensor 360 is a known value. The distancesD_(AL), D_(AR), D_(BL), D_(BR) between the first matrix optical sensor340 or the second matrix optical sensor 360 and the left eyeball 400L orthe right eyeball 400R are measured by the above method. With these dataand trigonometric functions, the vertical distances e_(L), e_(R) betweenthe left eyeball 400L, the right eyeball 400R and the display panel 320may be calculated, thus the backlight of the display panel 320 and thefont size on the image are adjusted accordingly.

In addition, in an embodiment, when eyes are closed, it is hard todistinguish the eye white 420 area and the pupil 442 area from the graphshowing the change of reflected light energy measured by the firstmatrix optical sensor 340 and the second matrix optical sensor 360. Wheneyes are open, the eye white 420 area and the pupil 442 area may bedistinguished from the graph showing the change of reflected lightenergy measured again, thus whether the eyes are blinking and theblinking frequency may also be detected.

The first matrix optical sensor 340 and the second matrix optical sensor360 may convert the light into electric charge, then into digitalsignal. In a preferable embodiment, the first matrix optical sensor 340and the second matrix optical sensor 360 may be, but not limited to aCCD (charge coupled device) sensor, a CMOS (complementary metal-oxidesemiconductor) sensor, an infrared sensor, a weak laser sensor or adigital camera module. Its detecting manner is, but not limited tophoto, scanning or interlacing type. In addition, single matrix opticalsensor is enough to perform the function of the eyeball locating system300, while multiple matrix optical sensors may improve the accuracy.

The eyeball locating system 300 is used in the electrical device withthe display panel 320, such as digital camera, projector, automatedteller machine (ATM), media or medical instrument. For example, disposea matrix optical sensor of the eyeball locating system 300, such as thefirst matrix optical sensor 340, inside the display panel 320 of theelectrical device and set up the application program 380 in its memory(not shown). After the first matrix optical sensor 340 detects thereflecting light from the surface of the eyeball 400, the applicationprogram 380 calculates the graph showing the change of reflected lightenergy and the characteristic value by the microprocessor of theelectrical device, so as to handle the electrical device.

The possible application of the embodiment of the present invention isfurther illustrated as follows: the movement of the eyeball 400 controlsthe cursor and the blinking defines the shortcut. The blinking speed andnumber define shortcuts, such as: blinking right eye for confirmationand blinking left eye for cancellation. The intensity of the backlightis adjusted by determining the size of the pupil 442. The change of thepupil 442 is measured by determining the wave, so as to adjust thebrightness of the backlight. If no user, the embodiment of the presentinvention may use to detect the environment, transfer specialadvertisement and message or even close the computer.

As shown in FIG. 9, the eyeball locating system 300 has an eyeballlocating method, including: providing a default graph C showing thechange of light energy (S1); defining a default characteristic value ofthe pupil 442 according to the default graph C showing the change oflight energy (S2); shining light on the eye white 420 and the pupil 442and making at least a part of the light be reflected by the eye white420 and the pupil 442, so as to form a reflecting light (S3); detectingthe energy of the reflecting light from the eye white 420 and the pupil442 (S4), so as to form a measured graph C1, C2, C3 or C4 showing thechange of reflected light energy (S5); calculating a measuredcharacteristic value of the pupil 442 according to the measured graphC1, C2, C3 or C4 showing the change of reflected light energy (S6); andcomparing the default characteristic value with the measuredcharacteristic value (S7) to determine the change of the pupil 442(S8)according to the difference between the default characteristic value andthe measured characteristic value.

In an embodiment, the step of comparing the default characteristic valuewith the measured characteristic value to determine the change of thepupil 442 includes determining the width, displacement or area change ofthe pupil 442. Furthermore, the step of determining the displacementchange of the pupil 442 includes determining the vertical displacement,horizontal displacement and near-far displacement of the pupil 442.

In an embodiment, the time difference between the light traveling fromthe matrix optical sensor 340 or 360 to the surface of the eyeball 400and it being reflected to the matrix optical sensor 340 or 360 from thesurface of the eyeball 400 is measured. According to the light speed andthe time difference, the distance between the matrix optical sensor 340or 360 and the eyeball 400 is calculated.

The eyeball locating system 300 is used to avoid touching products.Besides closer to the special requirement of general user, it is moresuitable for the disabled men and to avoid the bacterial diseases.

The foregoing description of the preferred embodiments of the inventionhas been presented for purposes of illustration and description. It isnot intended to be exhaustive or to limit the invention to the preciseform or to exemplary embodiments disclosed. Accordingly, the foregoingdescription should be regarded as illustrative rather than restrictive.Obviously, many modifications and variations will be apparent topractitioners skilled in this art. The embodiments are chosen anddescribed in order to best explain the principles of the invention andits best mode practical application, thereby to enable persons skilledin the art to understand the invention for various embodiments and withvarious modifications as are suited to the particular use orimplementation contemplated. It is intended that the scope of theinvention be defined by the claims appended hereto and their equivalentsin which all terms are meant in their broadest reasonable sense unlessotherwise indicated. Therefore, the term “the invention”, “the presentinvention” or the like does not necessarily limit the claim scope to aspecific embodiment, and the reference to particularly preferredexemplary embodiments of the invention does not imply a limitation onthe invention, and no such limitation is to be inferred. The inventionis limited only by the spirit and scope of the appended claims. Theabstract of the disclosure is provided to comply with the rulesrequiring an abstract, which will allow a searcher to quickly ascertainthe subject matter of the technical disclosure of any patent issued fromthis disclosure. It is submitted with the understanding that it will notbe used to interpret or limit the scope or meaning of the claims. Anyadvantages and benefits described may not apply to all embodiments ofthe invention. It should be appreciated that variations may be made inthe embodiments described by persons skilled in the art withoutdeparting from the scope of the present invention as defined by thefollowing claims. Moreover, no element and component in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element or component is explicitly recited in the followingclaims.

1. An eyeball locating method for measuring the movement of an eyeballcomprising an eye white and a pupil, comprising the steps of: providinga default graph showing a change of light energy of an eyeball; defininga default characteristic value of the pupil according to the defaultgraph showing the change of light energy; shining light on the eye whiteand the pupil wherein at least a part of the light is reflected by theeye white and the pupil, so as to form a reflecting light; detecting theenergy of the reflecting light, so as to form a measured graph showingthe change of reflected light energy; calculating a measuredcharacteristic value according to the measured graph showing the changeof reflected light energy; and comparing, using a program stored in acomputer-readable medium, the default characteristic value with themeasured characteristic value to determine the change of the pupil andto measure the movement of a eyeball.
 2. The eyeball locating method ofclaim 1, wherein the default characteristic value is a default contrastratio between the eye white and the pupil, and the measuredcharacteristic value is a measured contrast ratio between the eye whiteand the pupil.
 3. The eyeball locating method of claim 1, wherein thedefault characteristic value is a default width of the pupil, and themeasured characteristic value is a measured width of the pupil.
 4. Theeyeball locating method of claim 1, wherein both the default graphshowing the change of light energy and the measured graph showing thechange of reflected light energy show the relationship between the lightreflectivity and time.
 5. The eyeball locating method of claim 1,wherein the step of comparing the default characteristic value with themeasured characteristic value to determine the change of the pupilcomprises: determining the width, displacement or area change of thepupil.
 6. The eyeball locating method of claim 5, comprising determiningthe displacement change of the pupil, wherein the step of determiningthe displacement change of the pupil comprises: determining a verticaldisplacement, a horizontal displacement or a near-far displacement ofthe pupil.
 7. The eyeball locating method of claim 1, further comprisingthe steps of: providing a matrix optical sensor for shining the lightand detecting the energy of the reflected light; measuring the timedifference between the light emitted from the matrix optical sensor andthe reflecting light coming back to the matrix optical sensor; andcalculating the distance between the matrix optical sensor and theeyeball according to the light speed and the time difference.
 8. Aneyeball locating apparatus for measuring the movement of an eyeballcomprising an eye white and a pupil, comprising: a display panel; amatrix optical sensor, disposed in the display panel, for shining lighton the eyeball, wherein at least a part of the light is reflected by theeye white and the pupil to form a reflecting light, and detecting theenergy of the reflecting light; and an application program, providing adefault graph showing the change of light energy of the eyeball todefine a default characteristic value of the pupil, and controlling thematrix optical sensor to detect the energy of the reflecting light, soas to form a measured graph showing the change of reflected light energyaccording to the energy of the reflecting light, wherein the applicationprogram calculates a measured characteristic value according to themeasured graph showing the change of reflected light energy and comparesthe default characteristic value with the measured characteristic valueto determine the change of the pupil and to measure the movement of aeyeball.
 9. The eyeball locating apparatus of claim 8, wherein thematrix optical sensor is disposed at one side of the display panel. 10.The eyeball locating apparatus of claim 8, wherein the matrix opticalsensor is selected from the group consisting of a charge-coupled devicesensor, a complementary metal-oxide-semiconductor sensor and an infraredsensor.
 11. The eyeball locating apparatus of claim 8, wherein thedefault characteristic value is a contrast ratio between the eye whiteand the pupil, a width, a displacement, or an area of the pupil.
 12. Theeyeball locating apparatus of claim 8, wherein the measuredcharacteristic value is a contrast ratio between the eye white and thepupil, a width, a displacement, or an area of the pupil.
 13. The eyeballlocating apparatus of claim 8, wherein both the default graph showingthe change of light energy and the measured graph showing the change ofreflected light energy show the relationship between the lightreflectivity and time.
 14. The eyeball locating apparatus of claim 8,wherein the application program compares the default graph showing thechange of light energy with the measured graph showing the change ofreflected light energy to determine the distance change between thematrix optical sensor and the eyeball.
 15. The eyeball locatingapparatus of claim 14, wherein the application program adjusts abacklight of the display panel or a font size on an image shown by thedisplay panel according to the distance change between the matrixoptical sensor and the eyeball.
 16. The eyeball locating apparatus ofclaim 8, wherein the application program measures the time differencebetween the light emitted from the matrix optical sensor and thereflecting light coming back to the matrix optical sensor, andcalculates the distance between the matrix optical sensor and theeyeball according to the light speed and the time difference.
 17. Theeyeball locating apparatus of claim 16, wherein the application programadjusts a backlight of the display panel or a font size on an imageshown by the display panel according to the distance change between thematrix optical sensor and the eyeball.